1. Field of the Invention
The invention relates to a hold-down device for a brake shoe guided on an anchor plate of a drum brake, comprising
a pin which passes through a hole each in the anchor plate and in a web of the brake shoe and which includes a foot resting on the anchor plate and a head, and further comprising
a spring assembly disposed between the head and the web and including a receiving portion which is formed with a recessed seat for the head and with a slot which serves for radially slipping the receiving part on to the pin and is defined by a pair of outer edges and a pair of adjoining inner edges.
2. Discussion of the Background
Such a hold-down device is known from GB-A 899 061. The head of the pin in that case is designed like a hammer head, and a C-shaped leaf spring having two limbs disposed symmetrically with respect to each other and interconnected by an apex region, while having a bent-up edge each at their respective free ends remote from the apex, presents the spring assembly. Starting from that edge, each limb rises in the direction of the apex up to a wavy elevation which is parallel to the apex; that is followed by a cylindrical depression, likewise parallel to the apex, extending transversely across the full width of the respective limb. Each of the two limbs is formed with a slot starting from the upwardly bent edge, extending at uniform width up to the depression, and terminating beyond the same in a semicircular arc. When mounting this known hold-down device, the slotted part of the limb remote from the web of the corresponding brake shoe constitutes a receiving part which by and large is pushed under the hammer head formed at the pin until the hammer head, lying transversely with respect to the slot, becomes locked in the cylindrical depression. Now, if the hammer head deviates from the transverse orientation with respect to the slot, either from the beginning or because the pin has rotated ever so slightly about its axis during assembly, it is no longer guaranteed that the mounting will be correct. The hammer head perhaps may come to a stop on the elevation and slip off in outward direction along the limb later on due to vibrations, for example. Or it may fall through the slot. In both events the C-shaped leaf spring and, therefore, the entire hold-down device become ineffective. To prevent that, the hold-down device must be mounted manually with great care and the mounting verified by an independent person, whenever possible, before the drum brake can be released for further installation.